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4.
The History (1908-1955) The Chisso Corporation opened a chemical factory in Minamata in 1908 Minamata is a city located in Kumamoto prefecture, Japan Chisso chemical factory initially produced fertilizers Following the nationwide expansion of Japan’s chemical industry, the company branched out into the production of acetylene, acetaldehyde, acetic acid, vinyl chloride and octanol The Minamata factory became the most advanced in all of Japan

5.
The History (1908-1955)  The rapid expansion of the Minamata factory spurred on the local economy  Chisso prospered, so did Minamata  Chisso had great influence in Minamata  In 1932, Chisso Minamata factory first started acetaldehyde production  Producing 210 tons per year  By 1951, production had jumped to 6,000 tons per year  Over half of Japan’s total output

6.
The History (1908-1955) The chemical reaction used to produce the acetaldehyde used mercury sulfate as a catalyst A side reaction of the catalytic cycle led to production of methylmercury Methylmercury is an organic mercury compound Methylmercury is a highly toxic compound Wastewater from the Chisso factory were released into Minamata Bay

8.
1956-1959 April 21, 1956, a five-year old girl was examined at Chisso’s factory hospital in Minamata Physicians were puzzled by her symptoms:  Difficulty walking, speaking and convulsions Few days later, eight other girls in the neighborhood were found experiencing similar problem On May 1, 1956, a discovery of an “epidemic of unknown disease of the central nervous system” was reported to the local public health Patients were isolated - leading to stigmatization and discrimination

9.
1956-1959 Cats were also seen to have convulsions, go mad and die Crows fell from the sky Fish floated dead on the sea surface The Kumamoto University Research Group was formed The disease developed without prior warning Patients lost sensation, and complained of numbness in hands and feet By October, 1956, 40 patients had been discovered, 14 had died

10.
1956-1959 The researchers figured the following:  staple food of victims was fish and shellfish from Minamata Bay  food poisoning by heavy metal  contaminated fish and shellfish as prime suspect Waste water from Chisso factory was suspected as the origin Initially, manganese was thought to be the causal substance British neurologist Douglas McAlpine suggested the Minamata symptoms resembled those of organic mercury Focus of investigation was shifted and centered on mercury

11.
1956-1959 In February 1959, mercury distribution in Minamata Bay was investigated Large quantities of mercury detected in fish, shellfish and sludge from the bay The highest concentration centered around the factory wastewater canal in Hyakken Harbour

12.
1956-1959 Hair samples of victims and Minamata residents were taken for tests The maximum mercury level recorded was 705 ppm This compared to an average level of 4 ppm for non- Minamata residents

14.
1959 Chisso came under closer scrutiny In order to deflect criticism, wastewater route was changed It discharged wastewater directly into Minamata River Minamata disease victims began to appear in other fishing villages up and down the coast of the Shiranui Sea

15.
1959 Chisso did not co-operate with the Kumamoto Research team Withheld information on its industrial processes Chisso factory’s hospital director, Hajime Hosokawa carried out his own experiments into Minamata disease Food to which factory wastewater had been added was fed to healthy cats He confirmed a diagnosis of organic mercury poisoning The company did not reveal this significant result to the investigators The company ordered Hosokawa to stop his research

16.
1959Compensation of fishermen and patients Minamata disease compensation agreements of 1959 The agreements were formulated outside the legal system by ad-hoc mediation committees Final agreements were weighted in favor of Chisso Punitive clauses in the agreements include: ‘’Representative groups of fishermen and Minamata disease patients could not make future claims for compensation against the company’’

17.
1959Wastewater Treatment System On October 21, Chisso was ordered to switch back its wastewater drainage to Hyakken harbour Installed a cyclator purification system at the factory On December 19, Chisso opened its purification system with a special ceremony Chisso’s president drank a glass of water supposedly treated to demonstrate it was safe But waste water from acetaldehyde plant still contained mercury Deception that the factory’s wastewater had been made safe was successful In people’s mind, the issue of Minamata disease had been resolved

19.
1959 - 1969 The years between the first set of agreements in 1959 and the start of the first legal action to be taken against Chisso in 1969 are often called the “ten years of silence” By late 1960, the Kumamoto and Kagoshima prefectural governments continued a joint survey into the level of mercury in the hairs of people living around the Shiranui sea Results showed that organic mercury had spread all around the inland sea

20.
1959 - 1969Continued Pollution Contaminated fish still poisoned people 50 ppm of mercury in people’s hair were discovered A highest recorded level was 920 ppm The prefectural governments did not publish the results, nor did anything in response to the survey A follow-up study ten years later discovered that many had died from “unknown causes”

21.
1959 - 1969 Congenital Minamata disease  Local doctors noticed for a long time an abnormal high frequency of cerebral palsy  A re-examination of children diagnosed with cerebral palsy was carried out  The symptoms of the children closely mirrored those of adult Minamata disease patients  However, many of their mothers did not exhibit symptoms  After several years of study and autopsy of two children, the doctors diagnosed an unrecognized congenital form of Minamata disease

22.
1959 - 1969Official government recognition On 26 September 1968, the government finally issued an official conclusion as to the cause of Minamata disease: “Minamata disease is a disease of the central nervous system, a poisoning caused by long-term consumption, in large amounts, of fish and shellfish from Minamata Bay. The causative agent is methylmercury. Methylmercury produced in the acetaldehyde acetic acid facility of Shin Nihon Chissos Minamata factory was discharged in factory wastewater... Minamata disease patients last appeared in 1960, and the outbreak has ended. This is presumed to be due to the fact that consumption of fish and shellfish from Minamata Bay was banned in the fall of 1957, and the fact that the factory had waste- treatment facilities in place from January 1960."

24.
Mercury Poisoning Methylmercury compound, inorganic compound consist of methyl and mercury It is a highly toxic substance It is a by-product produced from mercury sulfate Figure 1: Acetaldehyde manufacturing process using mercury

25.
Mercury PoisoningEffect of Methylmercury Compound on Human Health Methylmercury is absorbed 100% into the system through the intestines with oral intake Figure 3: Methyl mercury accumulation and its effect on human body

28.
Measures against Minamata PollutionControl measures Temporal variations in acetaldehyde production Final shut down of pollutant sources, by the total circulation system adopted in 1966 Figure 2: Changes in acetaldehyde production, mercury discharge, and Minamata disease cases

29.
Measures against Minamata PollutionEffluent Control Drainage of the Chisso’s factory effluent (containing methylmercury) to Minamata bay got regulated In 1970, “Water Pollution Control Law” was enacted The law enforced control of discharge of effluent in all water areas in Japan, in relation to toxic substances Conversion of production method was advised against caustic soda plants that might discharge mercury

30.
Measures against Minamata PollutionThe Water Pollution Control LawThe objective of the law is to: Prevent pollution of water in the public water areas Regulate effluent discharge by factories into public water areas Protect human health and preserve the living environment Protect sufferers, by incorporating provisions for compensation for damages

38.
Pouring its wastes into the air as well as the waters, the Chisso chemical complex dominates the city of Minamata In Japanese, "Chisso" means nitrogen

39.
Waste chemicals, dumped into the bay, worked their way up the food chain to thepeople of the city and caused what has come to be known as Minamata Disease

40.
Here we see an image of an outwardly healthy mother bathing her fetal-poisoned 16 year old daughter, Tomoko Uemura, physically crippled since birth due to environmental industrial mercury poisoning in the local Minamata, Japan, water supply

41.
Here, fishing on the Bay of Minamata. This scene has changed very little over the centuries.However, the pollution has changed the relationship that the people of Minamata have with the sea and their mainstay of fish

43.
The signing of an agreement between patients’ associations and Chisso

44.
Plaintiffs demonstrate with photos of their dead on the last day of the trial in October of 1972

45.
An aid mops the brow of Chissos - then President - Shimada, after he performed the Japanese ritual of shame and apology: touching his forehead to the ground, at the close of a grueling day in court